Merrill Lock No. 6
Why it's listed
Built of brick on concrete piles between 1892 and 1904, the Merrill Lock No. 6 complex on the Ohio River at Midland comprises a three-story power house with two nearly identical 2½-story lockkeeper and crew houses. The power house, which held machinery for the lock gates and water tanks in its tower, has deep brick arches, a slate roof on wood trusses and a cantilevered bay window giving views up and down the river. The lock was the second of ten built on the Ohio between Pittsburgh and Steubenville, and it entered operation in August 1904 with a nine-foot pool. The complex is regarded as the only surviving example of such dam and lock support buildings on the Ohio River in Pennsylvania. It was replaced by the Montgomery Lock and Dam in June 1936, after which the buildings were left vacant. The lock is associated with the canalization of the Ohio River and its role in regional freight transport.
Significance in brief: The nomination argues the complex is significant in architecture, engineering and transportation. It is described as the only surviving lock and dam support buildings of this kind remaining on the Ohio River in Pennsylvania. The lock and dam system is presented as having allowed economical transport of goods between Pittsburgh and western markets along the Ohio and Mississippi rivers.
Machine-generated summary. This summary was generated by a language model from the official nomination document and has not been reviewed line by line by an editor. It may contain errors. Check the source document before relying on any detail. Source: nomination document (PDF) · National Archives catalog entry. NRHP reference 80003410, listed September 4, 1980. Summary generated October 2026 (model claude-haiku-5-5, prompt v1.1-2026-10-29, confidence medium).
Key facts
| Address | E of Midland on PA 68, Ohioview Township, Midland |
|---|---|
| County | Beaver County |
| Listed | September 4, 1980 |
| Reference number | 80003410 |
| Resource type | Structure |
| Period of significance | 1892-1904 |
| Architectural style | Victorian with Richardsonian Romanesque influence |
| Criteria |
|
| Areas of significance | Transportation, Architecture |
| Level of significance | Local |
| Status (as stated in the nomination) | Abandoned and vacant since 1936; only the bank wall of the lock remains intact. |
| Acreage | 2.4 |
| Coordinates | 40.66866, -80.35145 (NPS GIS) |
What listing means for this property
National Register listing is honorary: it recognises significance and does not restrict what a private owner may do without federal money or permits. It unlocks the 20% federal rehabilitation tax credit for income-producing buildings, state credits in many states, and Section 106 review when federal agencies are involved. See what listing means in practice.
Noted as vacant in the nomination. Nomination documents can be decades old; current status may differ. If you are considering buying an empty listed property, read the due-diligence checklist.
General information, not legal or tax advice. Rules change; confirm with your State Historic Preservation Office or a qualified adviser.
Sources and further reading
- National Park Service, National Register of Historic Places database (snapshot May 2026), reference 80003410.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q1922027
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.